Tie Knot Ninja is a compendium of the different ways to tie a neck based garment. There are many ways of tying ties and crafting cravats beyond your widely-used windsor...I just can't remember them all off the top of my head.
Have you got a knot to suggest or any feedback on the knots listed here?
A good place to start.
This fellow on youtube has many many videos I shall have to index here properly.
Another youtube fellow with even more videos.